The majority of Americans own a cell phone. According to an association representing the wireless telecommunication industry, in 2007, 82.4% of Americans owned at least one portable electronic communication device, such as a cell phone or a personal digital assistant (PDA). As cell phones become more prevalent, and with these devices becoming integrated into everyday life, the chances of leaving or losing them increases. Similarly, other personal objects such as wallets and purses are even more ubiquitous, and are also prone to disadvantageously being left behind or lost.
There are many situations in which a person wants to be sure to have all their important personal items with them when entering or leaving an area or location. Usually these locations are those most often frequented by the owners of such personal items. If people could be assured of having their personal items when entering or leaving their house, office, or vehicle, the likelihood of forgetting or losing such an item becomes much less likely.
Products are in the market currently to help people find items that have been misplaced. The product FIND ONE FIND ALL® by Melbourne Designs, LLC, of Arlington, Tex., for instance, exemplifies systems using tracking devices that can be put on a cellular phone, wallet, or keys. Such systems, which include avalanche rescue modules, can track other devices or themselves be tracked by other devices. They are typically equipped with RF-emitting and perhaps RF-detecting attachments. When an object needs to be found, the user indicates such by putting one of the devices into “find” mode and using the RF-detecting means to locate the lost article that is emitting an RF signal or sound by which it can be found.
Other products in the market also try to prevent separation in the first place. They often operate by linking devices together to prevent a user from inadvertently leaving one behind. Such linked devices output an alarm when one of the paired objects is out of proximity of one another. U.S. Pat. No. 7,002,473 refers to a monitoring device, such as a cellular phone with included RFID reader that monitors objects equipped with RFID tags. The cellular phone outputs an alarm when any of the objects is not within proximity to the reader. This prior art system disadvantageously requires that the user of the system carry the interrogation device with him or herself.
Attempts have been made that pair objects to track one another, or a master device tracking a slave device. For instance, U.S. Pat. No. 6,265,974 refers to monitoring the spatial relationship between two communication devices for the purposes of preventing a child from becoming lost. The system works by producing alarm when the child is a certain distance from the parent when the device is in motion. Similarly, U.S. Pat. No. 5,781,109 relates to a paired alarm system, which would output an audible alarm when one unit is separated from one another. There is a need for a system that interrogates for a plurality of items and performs certain functions in response to whether or not the items are within range.
Other attempts, such as U.S. Pat. No. 6,967,576, relates to general location tracking with alarm output using a tracking device that communicates with objects to be tracked via electronic beacons. Alerts are sounded if the distance between the tracking device and the object to be tracked increase past a threshold and if the location of the tracking device is outside a defined area such as a house. U.S. Pat. No. 7,009,512 also relates to two devices monitoring distances between one other. In both cases, such prior art uses tracking devices for a user to carry as opposed to in a particular location or area.